Double-speed wrench



J. P. FIRPO. DOUBLE SPEED WRENCH APPLICATION FILED MAY 6. 191 B.

1,304,756. Patented May 27, 1919.

INVENTOR.

John P. Fir a0 BY hxm x ATTORNEY JOHN P. FIRPO, OF STOCKTON, CALIFORNIA. 1

DOUBLE-SPEED WRENCH.

Specification of Letters Patent.

Patented May 27, 1919.

Application filed May 6, 1918. Serial No. 232,890.

To all whom it may concern:

Be it known that I, JOHN P. FIRPo, a citizen of the United States of America,

residing at Stockton, in the county of San Joaquin and State of California, have invented certain new and useful Improvements in Double-Speed Wrenches; and I do declare the following to be a clear, full, and exact description of the same, reference being had to the accompanying drawings, and to the characters of reference marked thereon, which form a part of this application.

This invention relates to improvements in wrenches, particularly to that type commonly known as an offset wrench in which there is one fixed jaw and one jaw slidable relative thereto in order to alter the space between the jaws to fit different sized nuts or other members. The movable jaw is now advanced relative to the fixed jaw by a single worm engaging a pinion bar on the shank of the wrench. This worm is usually mounted directly within the movable jaw so that as the worm is moved the jaw will be advanced in either direction on the shank of the wrench.

By my improved invention,I aim to have a double acting worm whereby the speed of the slidable jaw will be developed so that much quicker adjustments thereof can be made.

A further object of the invention is to produce a simple and inexpensive device and yet one which will be exceedingly effective for the purposes for which it is designed.

These objects, I accomplish by means of such structure and relative arrangement of the parts as will fully appear by a perusal of the following specification and claim.

On the drawings, similar characters of reference indicate corresponding parts in the several views.

Figure 1 is a side elevation of an adjustable ofiset wrench showing my improved attachment.

Fig. 2 is an enlarged detached view of the movable jaw shown in Fig. 1.

Fig. 3 is a cross section taken on a line 3-3 of Fig. 1.

Referring now more particularly to the characters of reference on the drawings, the numeral 1 designates the shank or handle of the wrench and 2 the head thereof. This head has a stationary jaw 2 projecting therefrom and is provided with a transverse slot 3 and with a transverse groove 4.

communicating therewith and opening out onto the face of the head 2 adjacent the jaw 2 This groove 4 is provided with 1n wardly projecting lugs 5 running lengthwise jaw member 6 slides in the groove 4, such portion being provided with grooves 7 in which the lugs 5 fit. Rack teeth 8 on the lower edge of the member 6 project into the slot 3. A left hand worm 9 is rigidly mounted centrally and lengthwise of the slot 3 and through a worm 10 which is movable within the slot and has knurled right hand teeth on the outside thereof meshing With the rack teeth 8. The worm 9 is held rigid with respect to the wrench head 2 by means of a key 11. Hence a movement of the worm 10 advances the jaw 6, which advancing movement is accentuated by the fact that the worm 10 is mounted on the oppositely pitched worm 9.

From the foregoing description it will readily be seen that I have produced such a device as substantially fulfils the objects of the invention as set forth herein.

While this specification sets forth in detail the present and preferred construction of the device, still in practice, such deviations from such detail may be resorted to as do not form a departure from the spirit of the invention, as defined by the appended claim.

Having thus described my invention, what I claim as new and useful and desire to secure by Letters Patent is A wrench comprising a shank, a fixed jaw thereon whose face is turned at a slight angle from the shank, said shank being provided with a transverse groove adjacent the jaw, and a transverse slot below the groove and communicating therewith, the groove and slot both being at right angles to the face 60 thereof. The lower portion of a slidable of the aw, a movable jaw having an extension thereon slidable in the groove and having rack teeth on its inner face projecting into the slot, a worm secured to the shank and projecting through the slot centrally thereof, and a second worm on the first worm and coacting therewith said second worm having knurled teeth on the outside thereof meshing with the teeth on the movable jaw, said knurled teeth being of a reverse pitch 10 from those on the first named worm.

In testimony whereof I aflix my signature.

JOHN P. FIRPO.

Copies of this patent may be obtained for five cents each, by addressing'the "Commissioner of Patents, Washington, J G. 

